Fingerprint sensing technology has become widespread in use and is often used to provide secure access to sensitive electronic devices and/or data. Generally, capacitive fingerprint sensors may be used to determine an image of a fingerprint through measuring capacitance through multiple capacitive sensing elements. The higher the capacitance, the nearer the surface of an adjacent or overlying finger to the capacitive sensing element. Thus, fingerprint ridges provide a higher capacitance to an underlying capacitive sensing element than do fingerprint valleys.
Data generated by a fingerprint sensor may be encrypted for security purposes and processed using a secure processor. A fingerprint match to a known fingerprint image may also be determined by the secure processor. In this manner, fingerprint data may be kept secure and may not be exposed unencrypted or unsecured to non-secure processors.
Fingerprint images may generally be considered to be made up of several ‘nodes’, with each node representing a region of the fingerprint image. Nodes may generally be overlapping, such that the nodes may be stitched together to form an entire fingerprint image.
Fingerprint sensors may be smaller than the fingerprint, and a user may be required to roll, swipe, or otherwise move their finger to expose different regions of the finger to the fingerprint sensor in order for the system to obtain a complete fingerprint image.